1. Field of the Invention
The present invention relates to a color filter and a method for fabricating the same. More specifically, the present invention relates to an inexpensive color filter with excellent display quality where pixels are flat, and a simple method for fabricating the same. The present invention further relates to an inexpensive liquid crystal display device provided with such a color filter having excellent color display performance.
2. Description of the Related Art
Color filters are an essential component for color display devices such as liquid crystal color display devices. They are fabricated by forming colored pixels on a substrate made of glass or transparent plastic. The colored pixels consist of pixels of three primary colors, red (R), green (G), and blue (B) arranged linearly or in a mosaic fashion. The size of each pixel is about 100 .mu.m. Some methods for forming such colored pixels have been proposed, including: a method where photosensitive R, G, and B colored pastes are applied and patterned with light; an ink jet method where non-photosensitive ink is injected to predetermined positions so as to color the positions; a screen printing method where colored ink is printed on a substrate with a printer, and an electrodeposition method where colored ink is electrodeposited on a substrate with transparent electrodes formed thereon.
In order to enhance the contrast of the pixels, a light-shading colored layer is formed between the pixels (i.e., on a non-pixel portion), forming a so-called black matrix. In TFT-driving type liquid crystal display devices, for example, such a light-shading colored layer is used to shade transistors and wirings. The width of the light-shading colored layer is several micrometers at narrower portions thereof and about 100 .mu.m at wider portions thereof. Such a light-shading colored layer is conventionally formed by etching a chromium film formed by evaporation or sputtering.
The conventional light-shading colored layer has poor ink repellency properties. Colored ink therefore tends into intrude to the light-shading colored layer, thereby preventing the pixels from being formed flat. To overcome this problem, methods for fabricating a color filter by an ink jet method or a printing method where a silicone resin layer is formed on a photosensitive resin layer to utilize the ink repellency of the silicone resin are disclosed, for example, in Japanese Laid-Open Patent Publication Nos. 4-123005, 4-123006, 4-123007, 4-151604, and 4-195102. According to such methods, however, three layers, i.e., the light-shading colored layer, the photosensitive resin layer, and the silicone resin layer need to be formed. Further, a process of developing the photosensitive resin is required. This increases the thickness of the resultant color filter (hence, a liquid crystal display device using the color filter), complicates the fabrication process, and increases the fabrication cost. Thus, a color filter using the conventional light-shading colored layer and the method for fabricating such a color filter have many drawbacks as described above.